Deep well pumping mechanism



June 2, 1942,. R. T. KNAPP DEEP WELL PUMPINGVMECHANISM Filed Jan. l0, 1939 2 Sheets-Sheet l /4 Tram/v5 Ks.

June 2, 1942. R, T. KNAPP 2,284,908

DEMD WELL- PUMPING MECHANISM Filed Jan. 1o, 1939 2 sheets-sheet 2 IIIIIII ing fluids.

Patented June 2, 1942 UNITED STATES PATENT orrlcr:

DEEP WELL PUMPING MECHANISM Robert T. Knapp, Pasadena, Calif., assigner of one-fourth to Rudolph A. Reik and one-fourth to Forrest 0. Reik, both of Los Angeles, Calif.

Application January 1o, i939, seria1N0.`25o,14s

11 Claims.

This invention relates to apparatus for pump- It is particularly adapted for use in Y pumping Oil or other liquids from deep Wells in which the liquid rises by natural hydrostatic pressure to relatively low levels. It relates to that type of pumping apparatus in which a compressed gas, such as air or the natural gas usually available lin the oil elds, or other compressed uid, `is introduced Ainto the lower portion of the well and utilized to force oil to the surface of the well by displacement' from a fluid-tight pumping chamber which is intermittently lled with oil from the well.

The pumping cycle in pumps of this type consists of two periods or phases. VDuring one phase the pumping chamber is being lled with oil from the well at a rate of flow determined largely by the standing level of theoil in the well and the rate of inflow of the oil from the oil-bearing strata. During the second phase the oil is being forced into the delivery conduit from the pumping chamber at a rate dependent upon the pressure of the pumping fluid. u u

One of the objects of this invention is to provide a control mechanism capable of adjustment to initiate the action of each phase immediately upon the termination of the action of the preceding phase. Y

Another object cf the invention is to provide an apparatusvand a method of operating it,

which will accommodate valves of relatively large effective flow capacity.

Another object is to provide yvalves which operate promptly and rapidly. n

Another object is to provide mechanism ,which will operate the valves controlling the application of the pumping lluid to the pumped liquid in a positive manner and independently of any influence bythe level of the oil in the well, or by the changing pressure conditions of the liquid incident to the pumping cycle.

Another objectfs to provide a fully chronometric control of the pumping cycle which will be independent of any reactive inuence by the conditions incident to the pumping cycle.,

Another object is to provide such a chronometric control which will be adjustable s o as to vary the duration of the complete cycle of pumping operations, or t0 vary the relative duration of the two phases of the cycle. Y Y

Another object is to actuate the mechanism effecting this type of independent chronometric control by a fluid under pressure, preferably obtained from the samel source as that from which the displacement pumping fluid is obtained.

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In order lto iirst apply fluid pressure to the liquid in the pumping chamber and subsequently remove the fluid pressure in the most rapid possible alternation, it is essential that two entirely separated conduits for the pumping fluid be provided: one, a supply conduit for conducting it under pressure to the pumping chamber, and a second or bleeder conduit for relieving the pressure of the pumping iluid in the pumping chamber during that phase of the pumping cycle in which the pumping chamber is being filled with a charge of liquid. It is further essential that the supply conduit be lled at all times with uid underv full pressure for the full length of the well so that compressed fluid may' be instantly available Vfor `application to the pumping chamber immediately upon the filling of the pumping chamber with liquid. This is best accomplished byproviding each `conduit with its own valve. Accordingly, in this invention separate inlet and outlet valves for applying and removing fluid pressure fromk the liquid in the pumping charr'iberA are located 'adjacent the pumping chamber' and are operated in an entirely chronometric fashion. This is made feasible by locating the chronometric mechanism adjacent the pumping chamber, which is in turn made a practical possibility by using a chronometric mechanism adapted to be motivated by the same compressed uid as that which is used to force the oil to the surface of the well.

It is, therefore, a further object of my invention to provide a fully chronometric valve control mechanism adjacent the pumping chamber which will operate two rapidly and simultaneously acting valves controlling vrespectively the inflow and outflow o f pumping fluid in separate conduits each of which extends to the pumping chamber.

`It is a further object of my invention to Vprovide ,a positively operated liquid intake `valve controlling the flow of liquid from the well into the pumping chamber which will preferably be chronometrically operated in timed relationship with the chronometric operation of the two valves controlling the inflow and outflow of pumping iiuid to and from the pumpingV chamber. These liquid intake valves in pumping apparatus of standard ,construction are check valves which are opened and closed by the changing .pressures of the liquid in the well upon the upper and lower surfaces of the valve. The operation of such check valves is characterized by a lag which shortens the effective period of liquid inflow from the well `and the effective period of expulsion of the liquid from the pumping chamber to the surface of the well, thereby decreasing the quantity of oil delivered during eachy pumping cycle. Also the resistance of the flow of the liquid during the period of the slow opening movement of check valves of this type .causes evolution of gas, if the liquid is petroleum. The evolution of gas decreases the amount of liquid inflow, and otherwise interferes with the effective operation of the pump. Furthermore, when or if the pressure difference falls below that required to operate such check valves, the capacity of the pump is decreased and the operative 'cycle may be prematurely terminated. In my invention,l the liquid inflow valve is preferably opened and closed positively by power-operated means and in timed relationship with the operation of the pumpinguid valves so that the inflow of liquid from the well into the pumping chamber and the outflow of spent lpumping fluid therefrom may be terminated, and the inflow of compressed pumping fluid` into'the pumping chamber m-ay be initiated, rapidly and simultaneously, and at the termination of the pumping phase of the cycle the first two flows may be initiated and the latter flow terminated rapidly and simultaneously.

Other objects of this invention are to provide a petroleum displacement pump, in which arrangement of the pumping chamber and Valves therefor is such as to permit a rapid lling of the chamber without the evolution of gas as the oil moves into the chamber; to provide an operating mechanism which will continue to function even though normal movements of the )pumping mechanism may be at times prevented due to interference of gravel, valve failure, or other cause; to provide a chronometri-c control mechanism which is proof against contamination and which will not stop on dead center; to provide a pumping mechanism which is well Iadapted for operation with other similar units with as many stages as may be necessary to produce the desired lift with the pressure of pumping fluid available, which can be installed within well casings of small diameter, and will handle liquids `containing sand or other abrasive material.

It is another object of my invention to provide a structural arrangement of parts adapted to accomplish the objects above set forth which will be inexpensive, compact, readily assembled, sturdy, and of such a character as to require a minimum of attention, repair, adjustment, and replacement of parts.

Other objects will be apparent from a reading of the following description and drawings.

In the drawings:

Fig. 1 is `a view in vertical longitudinal section and elevation of :a well and a pumping apparatus embodying my invention.

Fig. 2 is a diagrammatic vertical sectional view of the lower portion of the Well and apparatus.

Figs. 3 and 4 are vertical sectional views of two contiguous portions of the lower end of the pumping apparatus.

Fig. 5 is a central longitudinal vertical section of the control mechanism. l

Fig. 6 is a vertical sectional view of that lportion of the pumping apparatus shown in the upper end of Fig. 3, taken along the line 5-5 of Fig. 3.

Fig. '7 is a horizontal sectional view taken along the line 'l-'l of Fig. 4.

Fig. 8 is a fragmentary, central longitudinal vertical sectional view of the control mechanism shown with an additional pipe connection for operating a second pumping mechanism.

Referring to Fig. 1, a well casing ll extends from a ground level I2 to an underground strata i3 containing the oil or other liquid which it is desired to pump to the surface of the Well. This casing is provided with the usual perforations i4 for admitting the oil from the strata into the casing in which it rises by hydrostatic pressure and stands at a level l5. Within this casing is installed and appropriately suspended an oil delivery 'pipe or conduit I6 and an outer concentrioally assembled compressed gas pipe l1 spaced from the oil pipe IB to provide a chamber of annular cross section for the passage of compressed gas from the ground level to the pumping mechanism in the Well, where it is utilized to actuate the pumping mechanism. The oil flowing upwardly in the pipe I6 is led olf to any desired delivery or storage destination through a discharge pipe I8, and compressed .gas is supplied to the pipe Il from a suitable source such as a compressor I through a pipe 20. A pumping apparatus 2| is secured to and supported by the lower ends of pipes IG and Il in a manner to be presently described, and secured to this pumping apparatus and supported thereupon is a tubing 22 which extends upwardly to a point above the standing level I5 of the oil in the well and is concentrcally spaced Varound the pipe Il. It acts as a vent or bleeder pipe for the spent .compressed gas after it has performed its work of operating the pumping apparatus.

An explanation of the diagrammatic showing of the pumping apparatus in Fig. 2 will facilitate 'an understanding of its structure as shown in Figs. 3 to 7. The three conduits and tubing I6,.|1, and 22, which are actually concentrcally related, are for diagrammatic simplicity shown in vertical parallel relationship in Fig. 2. The showing of the pumping apparatus 2l is also diagrammatic in character. A pumping charnber 23 communicates with the oil in the well through a port 24; with the oil discharge, delivery, or lift pipe I 6 through a port 25; with the pipe l1 through a port 26; and with the vent tubing 22 through a port 21. The port 24 is provided with an inwardly and upwardly opening valve 28 which is preferably power operated and is so shown and described herein. The port 25 is provided with an upwardlyopening checlr valve 29 which opens whenV the pressure of the oil in the pumping chamber exceeds the pressure of the column of oil standing in the discharge pipe I6, 4and closes when the pressure in the pumping chamber falls below that of the discharge pipe. Valves 3U and 3| in the intake and outlet ports 26 and 2T respectively are mechanically connected and power operated by compressed gas intermittently delivered to them by a control mechanism 32 which lalso controls the intermittent delivery of operating gas to the power operated valve 28. This control mechanism is constructed and arranged, as will be presently explained, to, at one instant, simultaneously open the valves 28 and 3l 'and close the valve 30, and, at the instant of termination of a predetermined time interval thereafter, simultaneously close the valves 28 and 3l and open the valve 30.

Provision may be made for the delivery of compressed gas from the gas pipe Il to the oil delivery pipe I6 through a passage' 33 controlled by an adjustable valve 34. This valve may be adjusted from the ground level to vary the effective orice through which the gas may pass from the pipe I1 to the pipe I6. Gas injected into the oil column in this manner is mixed with the oil, lightening the weight ofthe column of oil in the pipe I6, and facilitating the work of the pumping apparatus in the manner of the standard gas lift pumps.

The control mechanism 32 is operated by cornpressed gas which it receives from the pipe I1. It is constructed to intermittently interrupt the flow of gas therein. After leaving the control mechanism, `the compressed gas is conducted to the three power-operated valves 28, 30, and 3I, each of which is operated in one direction by the application of the gas pressure and is automatically operated in the other direction upon release of the gas pressure when the flow of gas is stopped by the control mechanism 32. The control mechanism is practically unaffected by well conditions, being actuated and controlled solely by the effective pressure of the gas in the pipe I1. This effective pressure is the difference between the pressures on the high and low pressure sides of the control mechanism, which pressures are both substantially constant. The pressure on the high pressure side is compressor I9 and is practically unaffected at the lower end of the pipe I1 by the level of the oil in the well, or the level or pressure of the coil in the pumping chamber, or by any mechanical or other changes effected in the course of the operation ofthe pumping mechanism.

In explanation of why the pressure at the lower end of the pipe I1 is thus unaffected, we shall assume that the compressor develops a pressure of 500 pounds, which is a standard pressurefor gas-operated, deep welly displacement pumps, that the well is 4,090 feet deep, and that thepipe I1 is a 21/2" O. D. pipe. A simple scale computation, based on the drawings, will show that the available reservoir volume of the gas chamber in the pipe I1 bears a ratio to the available reservoir volume of the empty displacement chamber 23 of 340 to 1. Bearing Vin mind that the take-off pipe to the control mechanism 32 is teed, as will later appear, into the take-off pipe from the pipe I1 to the displacement chamber 23, at a point closely adjacent the lower end of the pipe I1, and also bearing in mind that the skin friction in the pipe I1 is negligible and that the take-off pipe to the chamber 23 and its orifice into that chamber, as may be seen in Fig. 4, are small, vand consequently the rate of flow therethrough into the displacement chamber 23 is low, it is demonstrable by formulae i expressing the laws governing pneumatic pressures and velocities that the drop in pressure at the T connection to the vcontrol mechanism 32 due tothe opening of the valve 30- is substantially less than of the pressure at the compressor, or substantially less than 25 pounds. This drop in pressure is for all practical purposes negligible in comparison to the impressed maximum pressure of 500 pounds and has no appreciable effect upon'the functional operation between the casing II and pipe I'I, extending from the top of the oil column I5 to a casing head IIa. A pipe 81a is provided to conduct the gas from the chamber 81 to the compressor I9 or other delivery point. The pressure of the gas within the 'chamber 81 is but slightly above atmospheric pressure, and under some conditions may even be below atmospheric pressure due to the suction exerted upon it by the compressor when the gas is led from the chamber 81 to the compressor.l In any event, the gas pressure within the chamber 81 is very low compared with that withinl the pipe I'I, and While the pressure of the 4chamber 81 varies slightly with the fluctuation of the oil level I5, it is substantially constant during the operation of the pumping apparatus. The effective gas pressure available for operating the vseveral valves and control mechanism of the pumping apparatus in a manner toA be presently explained is either the difference between the pressure in the pipe I1 and that in the chamber 81, or is the difference between the pressure in the pipe I1 and atmospheric pressure. It is apparent, therefore, that in either case it is substantially and practically independent of any changes in the level I5 of the column of oil in the well.

Immediately upon the opening of the valves 28 and 3l and the closing of the valve 30, oil flows freely into the pumping chamber under the hydrostatic action of the oil in the well casing and in the oil-bearing strata and rises in the pumping chamber. At a moment preferably just as the rising oil contacts the ports 26 and 21 and their associated valves 33 and 3l, the control mechanism, which has been previously adjusted to operate on a time cycle determined by the conditions of the installation, closes the valves 28 and 3| and opens the valve 32|. Compressed gas is then admitted to the pumping chamber, and the charge of oil or mixedA oil and gas therein lifts the Valve 29 and is forced through the delivery pipe I 6 to the surface of the well and out through the discharge pipe I3. After the pumping chamber is emptied by the action of the compressed gas, the control mechanism'again operates to open the valves 28 and 3| and close the valve 30, whereupon the process of recharging the pumping chamber and delivery pipe is repeated. The valve 29 at the end` of each expulsion of oil from the pumping chamber closes underpthe gravity action of the oil remaining in the delivery pipe IE, thereby preventing any back ow of oil and conserving the entire volumetric capacity of the pumping chamber'23 for the new charge of oil from the well.

Figs. 3 to 7 show the actual mechanical conabove explanationl of the diagrammatic Fig.'2.

The lower ends of the pipes I5 and I1 are threaded or otherwise secured to an adapter 35. The adapter has a central bore 36 communicating with the interior of the pipe I6. The lower end of the adapter is formed to provide a Y-branched pipe connection 31 into which are threaded or otherwise secured two oil delivery pipes 38. These pipes extend downwardly to a valve block 39 into which they are threaded or otherwise secured in communication with Vertical bores 40 and @I thereof and which they support in vertical position in the well. The upper Yend of this block 39 is externally threaded at 42 to receive the lower end 'of the vent tubing 22 which is supported by the block and extends upwardly to a point above the standing level of the oil in the well.

Into the lower ends of the bores 40 and 4I are threaded or otherwise secured oil delivery pipe sections 38a which are joined by means of a Y-branched connection 43 to a single oil delivery pipe section 44. This latter pipe section is coupled at its lower end to a check valve housing 45 formed with a valve seat 46 and contains the usual check valve ball 29a associated with the seat and limited in its upward movement by stops 41 suitably mounted in the housing 45. To the lower end of the housing 45 is coupled a strainer cylinder 48 provided with the usual perforations 48a to permit passage of the oil and exclude gravel and other foreign bodies. A frame element 49 of the oil intake valve 28 is threaded into a tapped hole I in the lower end of the strainer cylinder and is supported thereby. The valve 28 is made in two bell-shaped parts 52a, and 52D, threaded together at 53. An interior chamber 54 of the valve encloses an enlarged lower end 58 of the valve frame element 49 and is operatively connected thereto by tension springs 55 each of which is secured at its upper end to the frame element 49 and at its lower end to the valve wall. The upper part 52a of the valve is formed with a circular flange 56 positioned between a depending skirt 51 of the strainer section 4'8 and the frame element 49, a construction which serves to prevent heavier foreign bodies finding their way into the interior of the valve chamber 54.

The lower end of the valve frame element 49 is drilled to provide a downwardly opening cylindrical recess 59 which constitutes a piston chamber in which reciprocates a piston 68. A plunger pin 6I is integrally connected to the lower end of the piston 68 and is formed with a rounded end at its lower extremity which ts within a conforming internal recess 62 in the lower end of the wall of the valve part 52h.

An axial bore 18 of relatively small diameter in the frame element 49, communicating with a compressed gas conduit 1I at its upper end, servesto conduct compressed gas to the piston chamber 59. The piston 68, when gas is admitted to the piston chamber, forces the valve 28 downwardly against the action of the tension springs 55 which hold the valve in contact with the plunger pin 6I at all times, and retrieve the valve to its uppermost position when the pressure of the gas upon the piston is removed. The mating surfaces of the end of the pin 83 and the recess 62 are designed to permit a small rocking action of the valve about the end of the pin which is limited by the lateral play of the ange 56 between the frame element 49 and the skirt 51. This rocking action allows for misalignment of the valve on its seat and facilitates the dislodging of dirt which may be caught between the valve and its seat.

The extreme lower end of the valve is provided with a projecting tip 64 which splits into an annular stream the upwardly flowing oil in the port 24. Above this tip 64 the valve is formed with an annular, upwardly and outwardly sloping surface 65 which engages a replaceable valve seat 66 seated in a coupling 81. This coupling is secured at its upper end to a section of tubing 68 which is in turn externally threaded upon the lower end of the valve block 39. The tubing 68 is the means of support of the coupling 61 and denes between the valve block 39 and the coupling 61 the pumping chamber 23 in which are housed the oil delivery pipe 44 and intake valve 28 with their associated parts described above. This chamber also houses mechanism for operating the valves controlling the inflow and discharge of pumping fluid, as will be later described. A spider 68a secured between the tubing 68 and the strainer cylinder 48 serves to position the valve mechanism 28 coaxially with respect to the valve seat 66.

A strainer section 12 is threaded upon and supported by the coupling 61, and oil entering the production string through this strainer iiows upwardly through the port 24 in the coupling 61, and thence into the pumping chamber 23 by way of a streamlined annular passage 13 between the valve surface 65 and the valve' seat 66. When compressed gas or other pumping i'luid is introduced into the pumping chamber 23, and the valves 28 and 3I are closed, the oil will be forced out of the pumping chamber through the perforations 48a and the port 25, and after lifting the valve ball 29a it will be conducted to the surface of the well through the pipe section 44, Y branch 43, pipe sections 38a, bores 49 and 4I, pipe sections 38, Y branch 31, bore 36, and delivery pipe I6.

Compressed gas or other pumping fluid under pressure is conducted from the compressor I9 or other source through the pipe I1 to the adapter 35. The adapter is made with an annular chamber 14 which communicates with the interior of the lower end of the pipe I1. This chamber 14 is connected by a port 15 to a gas pipe 16 which is secured to and supported by the adapter 35 at its upper end and extends downwardly to the valve block 39 by which it is supported at its lower end by means of a threaded connection therewith in communication with a Vertical bore 11 in the block.V This bore extends through the block to the pumping chamber 23 and constitutes an inlet port for the compressed gas. The flow of gas through this port; is controlled by the upwardly opening valve 39 which engages a valve seat 18 screwed into an enlarged lower end 19 of the port. The gas pipe 16, bore 11, and aperture of the valve seat 18 are small relative to the cross-sectional area of the'gas chamber in the pipe I1, and the rate of ow therethrough is correspondingly retarded, even should the chamber 23 and pipe I6 be entirely empty and at atmospheric pressure. A valve stem 30a which is an integral extension of the valve 38 is slidably mounted in the valve seat 18 and Contacts at its lower end and rests upon a horizontal lever 86 which is pivoted at 8l to an extension 82 of the valve block 39. Since the upper face of the valve 30 is subjected to gas pressure at all times, the valve will remain closed except when it is moved upwardly by the mechanical action of the lever 80. When the Valve 30 is lifted by this lever, compressed gas ows into the pumping chamber. If at this same time the oil intake valve 28 is closed and there is no outlet in the upper part of the pumping chamber for the compressed gas, any oil standing in the pumping chamber is forced into the delivery pipe I6.

An annular chamber 83 between the tubing 22 and the gas pipe I1 is open at the upper end of the tubing 22 to the gas space 81 above the level I 5 within the well casing I I. This annular chamber is in communication with a chamber 84 between the adapter 35 and the valve block 39 by means of an annular passage 85 between the adapter 35 and the tubing 22. The adapter is supported laterally within the casing 22 by adapter lugs 86 positioned within this passage 85. Fluid ldischarged into the chamber 84 will then find its way upwardly through the passage 85 and the chamber 83 to the gas space 81. v The compressed gas admitted through the valve 30 to the pumping chamber is exhausted into the chamber 84 and thence into the gas space 81 by'way of the port 21 in the lower wall of the valve block 39 and a bore 88 which is an enlarged extension of the port 21 and extends to the upper horizontal wall of the valve block 39.

The iiow of gas through this port and bore is controlled by the downwardly opening valve 3| which coacts with a valve seat 90 at the lower end of the port 21 to prevent the escape of gas from the pumping chamber 23. A coiledV spring 9| is seated in the bore 88 between a stationary ring 92 and the upper end of a valve arm 93 and acts to press the valve away from its seat. The lower end of the valve. 3| is a piston 94 which reciprocates in a piston chamber 95 of a cylinder block 95 rigidly secured to the lower end of the valve block 39. The outer end of the lever 80 is disposed in a transverse slot 91 in the upper portion of the piston 94 and is provided with a bearing 98 adapted to have sliding engagement with adjacent surfaces of the slot 91, whereby the motion of reciprocation of the piston imparts an oscillatory movement to the lever 80, which in turn alternately raises-and permits the lowering of the valve 30.

The piston 94 is forced'upwardly against the action of the compression spring 9| when corn-v pressed gas is admitted to the piston chamber 95 through an axial bore 99 in the lower end of the cylinder block 99 from a gas pipe or conduit |00. This conduit branches from the conduit 1| which has already been described as a supply conduit for the piston chamber 59 of the oil intake valve 28. The conduit 1| receives its supply of compressed gas from the supply conduit 16 through a series of uid conductors, beginning with pipe |0| which is connected to the conduit 16 at |02 preferably closely adjacent the upper end of the pipe 16, and continuing with a gas filter |03, a pipe |04, the valve engine 32, a pipe |06, and a bore |01 in the valve block 39. The pipe |06 is threadedly or otherwise secured in the upper end of a bore |01, and the pipe 1| is threadedly or otherwise secured in the lower end of the bore |01.

The valve engine or control mechanism 32 is actuated solely by the energy of the compressed gas delivered to it through the pipe |04, and it performs the function of alternately supplying gas to and venting it from the pipe |06'and the valve operating cylinders connected thereto. Considering the succession of events from one gas-ow shut-off to the next gas-flow shut-off as one pumping cycle, that phase of the cycle which begins with the shut-oil and ends with the reestablishment of the iiow as the charging phase, and the remainder of the cycle as the pumping phase, the valve engine is so constructed and designed that it can be adjusted to increase or decrease within desired limits, depending upon conditions, the time interval occupied by each phase independently of the other phase. The engine exercises a chronometric control of the valves 28, 30, and 3|, 'causing them to operate on a predetermined time cycle, the length of which is entirely independent of well conditions, hydrostatic or velocity head of the oil in the Well, accidental sticking of one or more of the valves, viscosity or other qualities of the oil, depth of the well, variations in the head pumped against, or any variable factors whatever other than the effective pressure of the gas in the supply pipe |04 and the adjustment set within the engine,v which two factors alone determine the length of the cycle. As has been heretofore explained, the effective pressure in the pipe |04 is, for any given pressure at the compressor, substantially constant. Similarly, the length of each of the two phases of the cycle in absolute time is dependent solely on the effective gas pressure and the adjustment set, and the length of each phase relative to the other phase is dependent solely upon the adjustment set. During the charging phase in which the engine prevents the ow of compressed gas to the piston chambers 59 and 95, thevalve 28 is held open by tension springs 55, the valve 3| is held open by the compression spring 9|, and the valve v30 is held shut by pressure of gas on its upper surface, in the absence of any mechanical lifting pressure exerted upon the valve stem 30a by the lever 80, this lever occupying its lowermost position by virtue of its connection with the piston 94. With the valves in this position, oil will flow into the pumping chamber 23. At the end of the time interval for which the engine 32 is set, which preferably is whenthe oil level in the pumping chamber reaches the ports 26 and 21 and their associated valves 30 and 3| ,compressed gas is given a free path through the conduit |06 to the piston chambers 59v and 95, the three valves are reversed in position, and oil is forced by pneumatic pressure from the pumping chamber to the delivery pipe of the well. At the end of a second'time interval for which the engine is also set, which is preferably when the gas reaches the port 25 and the valve'29, the flow of compressed gas is again shut off, the delivery flow ceases, and the charging of the pumping chamber is repeated. It is apparent that by knowing the position of the liquid level I5 with relation to the valve 28, together with the effective vis-A cosity of the liquid, the optimum length of time for both the charging and vdischarging operations can b e calculated and preset on the engine 32. The charging phase can be adjusted to exactly the length vof time required to ll the pumping chamber under the actual conditions of an installation. The pumping, lifting, or discharging phase can be adjusted to exactly the length of time requiredto deliver the charge into the delivery pipe under the given conditions of available gas pressure, well depth, and characteristics of the pumping apparatus. By such a calculated adjustment the pump can be caused to deliver oil at a maximum rate of flow.

The engine frame consists of an upper cylindrical block |08, a central cylindrical block |09, I

a lower cylindrical block ||0, an upper section of tubing threaded to and connecting the blocks |08 and |09, and a lower section of tubing ||2 threaded to and connecting the blocks |09 and H0. VThese sections dene, between the blocks which they connect, an upper chamber ||3 and a lower chamber ||4.

The engine supply conduit |04V is secured to the central block |09 in communication with a radial port H5, and the conduit |08` for conveying gas from the engine to the valves of Vthe pumping apparatus is secured to the central block in communication with a radial port H6. These ports I5 and I6 communicateat points near the longitudinal center of the blocku |09 with an axially disposed longitudinal bore ||1 which extends from end to end of the central block |09. A port ||8 of L-shaped conguration communicates with the axial bore ||1 at |20 and leads therefrom to the chamber H4. A port ||9 connects the port ||6 with the chamber ||3. Two radially disposed exhaust ports |2| and |22 connect the axial bere ||1 with the chamber 84 in which the valve engine 32 is mounted. Two ball cages |23 and |24 are suitably mounted in cylindrical recesses in the upper and lower walls, respectively, of the central block |09 in axial alignment with the bore ||1, and house respectively two valve balls |25 and |26 which have coacting relationship with two valve seats |21 and. |28 respectively formed at the opposite ends of the bore |l1. These valve balls control the passage of gas from the chambers ||3 and ||4 to the exhaust ports |2| and |22, which, when the corresponding valve ball is in the open position, takes place through a plurality of parallel, longitudinallyarranged ports |29 and |30 in the cages |23 and |24 respectively, then through disc-shaped chambers |3I and |32 respectively dened between the cages and the inner walls of the recesses in which the cages are mounted, and thence by the valve seats |21 and |28 to the exhaust ports I2| and |22. The chambers |3| and |32 and ports |29 and |30 also serve t0 connect the ports ||9 and ||8 with the chambers ||3 and ||4 respectively at all times.

A piston slide valve |33 is mounted in the bore ||1 and consists of two piston portions |34 and which snugly t the bore, a central cutaway portion l36, and two reduced end portions or pins |31 and |38 adapted to` engage and dislodge from their seats the valve balls |25 and |26. This over-all length of this piston Valve is such that when one valve ball is seated, the other is held near the outer portion of its cage. The disposition of the piston portions |34 and |35 and the intermediate cut-away portion |36 is such that when the ball |26 is seated, gas can pass fromthe port I5 to the port |18, and when the ball |25 is seated, gas can pass from the port ||5 to the port ||6.

The upper block |08 has a downwardly extending hollow cylindrical boss |39 in which is slidably mounted a plunger |49. A bellows |4| of fluid-proof material is mounted concentrically about the boss |39, being secured in fluid-tight manner between an annular flange |42 of the plunger and the lower wall of the block |08. Small ports |43 in the base of the boss |39 connect the interior with the interior of the bellows |4|. A coiled compression spring |44 seated in a cylindrical recess in the lower end of the plunger |40 presses downwardly upon a disc |45 which is limited in its downward movement by a recess cap |46. Rigidly secured to the disc |45 is a pin |41 slidably mounted in the cap |46 and which is adapted to engage the ball |25 and impart thereto a movement longitudinally of the engine.

At the other end of the engine the block ||0 is formed with an upwardly extending, axial, cylindrical projection |48 which fits within and has slidable engagement with a cylindrical recess |52 in the lower end of a plunger |49. A bellows similar to the bellows I4| is secured between an annular iiange |5| on the plunger |49 and the upper wall of the block H9. Radial ports |53 connect an axial bore |54 in the projection |48 and in the block ||0 with the interior of the bellows |50.

A compression spring |55 is mounted in an axially disposed cylindrical recess in the upper end of the plunger |49 and presses upwardly against a disc |55. A pin |51 rigidly secured to this disc slides within a recess cap |58 which limits the upward `movement of the disc and pin. The pin is adapted to engage the ball |26 andimpart a movement thereto longitudinally of the engine. A coiled compression spring |59,"which is seated between a ring |60 threaded on the plunger |49 and a ring |6| slidably tted within the tubular section ||2 and held against Vmovement therein by an inwardly projecting annular iiange ila. thereof, acts to urge the plunger upwardly at all times. Ports |62 serve to provide fluid communication between the portions of the chamber ||4 above and below the ring |6|. A conduit pipe |63 connects the bore |54 in the lower block with a similar axially disposed bore `|64 in the upper block which extends from the upper end of the block |08 to the interior of the boss |39. A slightly tapered constricted seotion |65 of this bore |64 affords a seat for a needle Valve |66. This needle valve is free to reciprocate within the bore section |65. Its reciprocatory movement is limited in one direction by engagement of its head |66a with the lower end of a hollow cylinder |61, the lower portion of which is longitudinally split at |6111, and the Y upper end of which has threaded engagement with an upper enlarged portion |68 of the bore |64. The cylinder can thus be longitudinally adjusted upon its threads within the bore portion |68. Its movement in the other direction is similarly limited by the lower end of a pin |69@ integrally formed with an adjustable stop nut |69 which is threadedly mounted within the cylinder |61. A light coiled spring |680l interposed between the nut |69 and the needle valve head |66a applies a slight downward pressure to the needle valve at all times. A threaded plug |10 closes the upper end of the bore |58, and upon its removal a suitable tool can be inserted within the bore for manipulating the adjusting cylinder |61 and the adjusting nut |69.

The engine operates in the following manner. The conduit |63, bores` |54 and |64, the interior of the boss |39, the recess |52, and the interior of the two bellows are lled with oil of a type suitable for hydraulic work. The spring |59 holds the piston valve |33 in its uppermost position when the engine is idle, and operation of the engine begins with the valve in this position. The spring prevents the valve |33 standing in a midway dead center position. When compressed gas is supplied through the conduit |04, it nds its way through the ports ||5 and ||8 to the chamber ||4 in which it builds up pneumatic pressure suflicient to urge downwardly the plunger |49 against the spring |59. The bellows |50 is shortened, and the oilwithin it and within the recess |52 is moved through the bore |54 and the conduit |63 to the bore |64. Here it flows downwardly through the constricted passage |65. The needle |66 is at this juncture at its lowermost position with its head |66a resting -upon the lower end of the adjustable cylinder- |61, where'it is held by the spring |68a. In this position the needle does not quite l] the passage |65, andV oil can slowly flow into the interior of the boss |39 and the bellows |4|. The plunger |40 moves slowly downward, and after a definite time interval, which is obviously determined by the position in which the needle |66 is held by the lower end of'the adjustable cylinder |61, the pin |41 contacts the ball |25, which at rst resiststhe pressure e'xerted'upon it by the pin because of upwardly acting gas pressure upon the ball |26. As a result, the spring |44 is compressed. When a tip |460l of the cap |46 comes in contact `with the ball |25, the seating of the ball |26 is broken, and then the spring |44, through the pin |41, causes the piston valve |33 to snap `to its lower position, in which the ball is seated. This spring |44 and the corresponding spring |55 prevent vthe Valve |33 stopping during its reciprocations at a midway dead center position. Until the piston valve is snapped from its upper to its lower position, the gas inthe chamber ||3 and in the conduit |06 is free to flow through the ports |29 and H9, respectively, to the chamber |3l, the bore ||1, and the exhaust port and thence to the gas space 81. ,v

After the piston valve has been snapped to its lower position, the escape of gas in the chamber I|3 is cut off at the valve seat |21. The piston section |34 closes the port ||8, and thev section uncovers the port ||6, allowing gas to flow from the conduit |64 to the` conduit |66 through which it is conducted-to the three valves of the pumping apparatus, as has been heretofore dc-A scribed, where the charge of oil in the pumping chamber is then pumped tothe delivery pipe. The port I9, which communicates with the port ||6, conducts gas to the chamber ||3, compressing the bellows |4| and reversing the movement of the oil through the pipe |63. The needle |66 is moved upwardly by hydraulic friction with and the pressure differential of the oil until its head contacts the pin |6911 of the adjustable stop nut |69, which'obviously permits the engine oil to flow to the lower end of the engine more rapidly than it fiowed to the upper end of the engine. Since it usually takes less time to discharge the charge of well oil from the pumping chamber to the delivery pipe by the pneumatic action of high pressure gas than it does to bleed and recharge the pumping chamber under the hydrostatic action of the oil in the well, it is desirable that the pumping phase of the cycle be of shorter duration than the charging phase. When the engine oil flows back to the lower end of the engine and to the interior of the bellows |59, the plunger |49 is raised, eventually snapping the piston valve |33 to its upper position, whereupon the cycle is repeated.

If desired, provision may be made for jetting compressed gas into the column of oil in the delivery pipe |6 to decrease the weightv of the column and thereby decrease the load on the valve 29, which, commingling with the oil in the discharge pipe I6, will assist in effecting the gas-lift action.

Where the diameter of the well ypermits,'the mechanism shown in Fig. 4 may be duplicated at the bottom of the well to afford a duplex acting pump to provide a continuous rather thanA an intermittent flow of oil. In such an installation, the gas pipe 16 and discharge pipe |6 are provided With branches (not shown) leading to the corresponding connections on the duplicate pumping mechanism, and suitable provision is made for venting the used operating gas into the chamber 84. By redesigning .the mechanism shown in Fig. 4, it can be fitted into a semicircular portion of the tubing section 68, and the duplicate mechanism installed in the other semicircular portion thereof; or, by arranging prop- 30, and 3| will be operated by application and pumping apparatus in the well known manner of gas lift pumps. In Fig. 3 is shown means for incorporating such a gas lift with a pumping apparatus constructed in accordance with this invention. Referring to the upper end of Fig. 3, a tapered slot 33 in the pipe i6 which is wider at its lower end permits gas to `flow from the annular chamber between the pipes l5 and |1 into the column of oil in the pipe l5. By rotating the pipe IE at the ground level it will turn on its threads within the adapter 35 and be raised or lowered to shorten or lengthen the effective portion of the slot 33 above the upper end of a packing nut |1| threaded on a flange |12 on the adapter. If desired, the cycle canbe so regulated, by regulation of the adjustable cylinder |61 and the adjustable stop-nut |69, that at the end of the discharge phase the valves will not be reversed until some gas has passed through the release of gas pressure thereto by means of a pipe |113 (see Fig. 8) leading from a port |14 (see Figs. 5 and 8) to the bore corresponding to the bore |91 in the mechanism shown in Fig. 4. It will be apparent that the valves of the duplicate mechanism will be operated in chronologically staggered fashion with respect to the valves of the mechanism shown in Fig. 4, and that while the Dump ing chamber of one mechanism is filling .with oil, that of the other will be discharging, and vice versa, providing a continuous flow of oil through the discharge pipe.

When such a duplicate pumping mechanism is not provided, the port |14 is closed with a plug` In the drawings and description, one embodiment of this invention has been set forth and described. Other embodiments will be apparent to those skilled in the art. I therefore do not limit myself to the particular embodiment herein shown. The invention is applicable to the pumping of liquids against any presure head, as wellv pumping mechanism and lift it to the next higher pumping mechanism.

I claim as my invention:

1.-In an apparatus for pumping liquids from wells: a submerged pumping chamber in the well communicating with the liquid in the well; a first conduit for discharging liquid and connecting said pumping chamber with the well surface; a first check valve between the liquid in the Well and the pumping chamber adapted to open inwardly of said chamber; a second check valve adapted to open outwardly from said chamber into said liquid conduit; a source of pumping fluid under pressure; a second conduit connecting said source with said pumping chamber; an outlet for said pumping fluid from said pumping chamber; inlet and outlet valves controlling the ow of pumping uid from said source to said chamber and from said chamber into said outlet; means operated by fluid under pressure for mechanically opening said inlet valve and concurrently closing said outlet valve; an energystoring retrieving means forV mechanically closing said inlet valve and opening said outlet valve; a fiuid operated means for closing said rst check valve; a third conduit conducting iiuid under pressure to said inlet and outlet valve operating means, and to said check valveclosing means for the concurrent actuation of said inlet and outlet valve operating means and said check valve closing means; and means for intermittently interrupting the -supply of 'fluid under pressure in said third conduit.

2. In an apparatus for pumping liquids from wells: a submerged pumping chamber in the well communicating with the liquid in the well; a first conduit for discharging liquid and connecting said pumping chamber with the well surface; a first check valve between the liquid in the well and the pumping chamber adapted to open inwardly of said chamber; a second check valve adapted to open outwardly from said chamber into said liquid conduit; a source of pumping iiuid under pressure; a second conduit connecting said source with said pumping chamber; an outlet for said pumping iiuid from said pumping chamber; inlet and outlet valves controlling the flow of pumping fiuid from said source to said chamber and from said chamber into said outlet; means operated by fluid under pressure for mechanically opening said inlet Valve and concurrently closing saidA outlet valve; an energystoring retrieving means for mechanically closing said inlet valve and opening said outlet valve; an energy-storing retrieving means for mechanically opening said rst check valve; a fluid operated means for mechanically closing said first check valve; a third conduit conducting fluid under pressure to said inlet and outlet valve operating means, and to said check valve closing means for the concurrent actuation of said inlet and outlet valve operating means and said check valve closing means; and means for intermittently interrupting the supply of fluid under pressure in said third conduit.

3. In an apparatus for pumping liquids from wells: a submerged pumping chamber in the well communicating with the liquid in the Well; a iirst conduit for discharging liquid and connecting said pumping chamber with the well surface; a first check valve between the liquid in the well and the pumping chamber adapted to open inwardly of said chamber; a second check valve adapted to open outwardly from said chamber into said liquid conduit; a source oi pumping fluid under pressure; a second conduit connecting said source with said pumping chamber; an outlet for said pumping fluid from said pumping chamber; inlet and outlet valves controlling the flow of pumping fluid from said source to said chamber and from said chamber into said outlet; means operated by' fluid under pressure for mechanically opening said inlet valve and concurrently closing said outlet valve; an energystoring retrieving means for mechanically closing said inlet valve and opening said Outlet valve; an energy-storing retrieving means for mechanically opening said iirst check valve; a iiuid perated means for mechanically closing said first check valve; a third conduit conducting iiuid under pressure to said inlet and outlet valve operating means, and to said check valve closing means for the concurrent actuation of said inlet and outlet valve operating means and said check valve closing means; and means for intermittently interrupting the supply of fluid under pressure in said third conduit, said means being chronometrically operated in a completely selfcontrolled manner and actuated by power continuously supplied at a substantially constant rate.

4. In an apparatus for pumping liquid from a well: a well casing within the well, closed at its lower end and extending above the surface of the liquid in the well, and provided with an aperture adjacent its lower end communicating with the liquid in the well; a rst valve controlling the ow of liquid in said aperture; a plug in said casing forming with the casing below said plug a pumping chamber and having four vertical ducts extending therethrough; a source of fluid under pressure at the surface of the well; a first conduit connecting said source with the first of said ducts; a second conduit connecting said rst conduit with the second of said ducts; a third liquid discharge conduit extending from the third of said ducts to the surface of the well; valves in the first and fourth of said ducts; mechanism for suitably operating said valves to alternately apply and remove fluid pressure to and from liquid in said chamber; iiuid pressure operated means mounted in said chamber for operating said mechanism; a fourth conduit connecting said second duct with said fluid pressure operated means; a fifth conduit extending from the lower end of said third duct downwardly within said chamber; an upwardly opening check valve in the lower end of said fifth conduit; and chronometric mechanism interposed in said second conduit adapted to intermittently interrupt the flow of fluid under pressure in said second conduit, said mechanism being adapted to be operated by the iiuid under pressure in said second conduit.

5. In an apparatus for pumping liquid from a well: a well casing within the well, closed at its lower end and extending above the surface of the liquid in the well, and provided with an aperture adjacent its lower end communicating with the liquid in the well; a rst valve controlling the flow of liquid in said aperture; a plug in said casing forming with the casing below said plug a pumping chamber, and having four vertical ducts extending therethrough; a source of fluid under pressure at the surface of the well; a rst conduit connecting said source with the first of said ducts; a second conduit connecting said first conduit with the second of said ducts; a third liquid discharge conduit extending from the third of said ducts to the surface of the well; valves in the first and fourth of said ducts; mechanism for suitably operating said valves to alternately apply and remove fluid pressure to and from liquid in said chamber; uid pressure operated means mounted in said chamber for operating said mechanism; a fourth conduit connecting said second duct with said fluid pressure operated means; a fifth conduit extending from the lower end of said third duct downwardly within said chamber; an upwardly opening check valve in the lower end of said fifth conduit; chronometric mechanism interposed in said second conduit adapted to intermittently interrupt the ow of fluid under pressure in said second conduit, said mechanism being adapted to be operated by the fluid under pressure in said second conduit; means actuated by fluid under pressure for operating said first valve; and a sixth conduit connecting said'fourth conduit with said meansfor operating said lirst'- valve.

' 6'. In an apparatusv for pumping liquid from Wells: a submerged liquid pumping chamber having a liquid intake port in its bottom Wall communicating with the liquidv in the well; a valve controlling the flow of liquid through said port; aliquid discharge conduit connecting' said pumping chamber with the surface of the. Well; an upwardly opening check valve insaid discharge conduit; intake and outlet fluid ports in the upper portion of said chamber; a valve in each of said ports; an upwardly extending bleeder conduit connected to said outlet fluid port; an upwardly extending first supply conduit connected to said intake fluid port; means for continuously supplying fluid under pressure in said first supply conduit to said fluid inlet port so as to tend to close said fluid inlet port valve; means adapted by a movement in one direction to open said fluid inlet port valve against the action of the fluid pressure in said first supply conduit and simultaneously close the iiuid outlet port valve, and by a movement in the other direction to siinultaneously reversely operate the valves; a pneumatic means for operating said valve operating means in said one direction; a mechanical energy-storing retrieving means for actuating said valve operating means in said other direction responsive to the termination of the operation of said pneumatic means; a second supply conduit connecting said first supply conduit with said pneumatic means; and means for intermittently interrupting the supply of fluid under pressure in said second supply conduit.

7. An apparatus as set forth in claim 6, and comprising in addition: completely self-controlled chronometric means for operating said interrupting means substantially unaffected by cyclic or other variations in the hydrostatic conditions of the pumped liquid.

8. In an apparatus for pumping liquid from Wells: a submerged liquid pumping chamber having a liquid intake port in its bottom wall communicating with the liquid in the well; a valve controlling the flow of liquid through said port; a first pneumatic means for closing said valve; a mechanical energy-storing retrieving means for opening said valve responsive to the termination of the operation of said rst pneumatic means; a liquid discharge conduit connecting said pumping chamber with the surface of the Well; an upwardly opening check valve in said discharge conduit; intake and outlet fluid ports in the upper portion of said chamber; a valve in each of said ports;v an upwardly extending bleeder conduit connected to said outlet fluid port; an upwardly extending rst supply conduit connected to said intake fluid port; ,means for continuously supplying fluid under pressure in said first supply conduit to said fluid inlet port so as to tend to close said fluid inlet port valve;

l means adapted by a movement in one direction to opensaid fluid inlet port valve against the action of the uid pressure in said first supply conduit and simultaneously close the fluid outletport valve and by a movement in the other direction to simultaneously reversely operate the valves; a second pneumatic means for operating said valve operating means in said one direction; a second mechanical energy-storing retrieving means for operating said valve operating means in said other direction responsive to the termination of the operation of said second pneumatic means; a second supply conduit connecting said Hm il Il first supply conduit with said first pneumatic means and'l with said second pneumatic means; and means for intermittently interrupting the supply of uid under pressure in said second supply conduit. Y

9.An apparatusas set forth. in claim 8 and comprising in addition: completely self-controlled chronometric means for operating said interrupting means substantially unaffected by cyclic or other, variations inthe hydrostatic conditions of the pumped liquid.

10. In a well having a well bore of substantially uniform diameter, the combination of: a tubing of suflicient diameter to be inserted in said Well; walls forming a pumping chamber carried by said tubing and adapted to be submerged inside said well in the liquid in said well when said tubing carrying said chamber is lowered into said well; a liquid inlet valve so situated as to close a liquid inlet passage through which liquid may flow from said Well into said chamber, said liquid inlet valve being so placed that it tends to open whenever liquid tends to flow from the well into the chamber and tends to close whenever liquid tends to flow from said chamber back into the well; a gas inlet valve so situated that it can close a gas passage through which gas can be admitted to said chamber from a source of gas supply; a relief valve so situated that it can close a relief passage through Which gas may liow from said gas chamber to the space outside said tubing above the fluid in the well; a check valve so placed that it can close a liquid delivery passage through which liquid may flow from said chamber to a point above the surface of the ground, said check valve being so constructed that it automatically closes to prevent liquid from flowing from said delivery passage to said chamber and automatically opens to allow liquid to pass from said chamber to said delivery passage; a fluid actuated valve means for operating said gas inlet valve; a uid actuated valve means for actuating said relief valve; a pilot valve so formed as to supply fluid under pressure to actuate all of said fluid actuated valve means and cause said gas inlet valve and said relief valve to operate in the proper sequence; a fluid actuated pilot valve operating means for operating said pilot valve; and chronometric means for controlling the application of fluid pressure to said fluid actuated .pilot valve means and thus controlling the time used in performing each step of the operating cycle.

1l. In a Well having a well bore of substantially uniform diameter, the combination of a tubing of sufcient diameter to be inserted in said well; walls forming a pumping chamber carried by said tubing and adapted to be submerged inside said well in the liquid in said well when said tubing carrying said chamber is lowered into said well; a liquid inlet valve so situated as to close a liquid inlet passage through which liquid may ow from said Well into said chamber, said liquid inlet valve being so placed that it tends to open whenever liquid tends to flow from the well into the chamber and tends to close whenever liquid tends to flow from said chamber back into the well; fluid actuated valve means for positively causing said fluid inlet valve to open and close; a gas inlet valve so situated that it can close a gas passage through which gas can be admitted to said chamber from a source of gas supply; a relief valve so situated that it can close a relief passage through which gas may flow from said gas chamber to the space outside said tubing above the fluid in the Well; a check valve so placed that it can close a liquid delivery passage through which liquid may flow from said chamber to a point above the surface of the ground, said check valve being so con structed that it automatically closes to prevent liquid from flowing from said delivery passage to said chamber and automatically opens to al- 10W liquid to pass from said chamber to said delivery passage; a fluid actuated valve means for operating said gas inlet valve; a fluid actuated `valve' means for actuating said 'reliecf valve; a pilot valve so formed as to supply fluid -under pressure to actuate'all of said fluid actuated valve means and' causegsaid `fluidinlet valve, said gas inlet valve, and said relief valve to operateV in the propersequen'ce; a iluid actuated pilot valve operating means for operating said pilot valve; and chronometricmeans for controlling the application of "uid pressure to said fluid actuated pilot valve means and thus .icontrolling the time used ,in performing each step of the operating cycle'. 1 j

ROBERT T. KNAPP;

CERTIFICATE OF CORRECTION.

Patent No. 2,28Ll.,90`8. June 2, 1914.2.

ROBERT T. KNAPP.

It is hereby certified that error appears in the printed specificationof the above numbered patent reqnring correction as follows: Page 5, first column, lne,26,.after' "is" insert --generated by the; and thet the said Letters Patent should be read with this corecton therein that the same may conform to the record of the case in the Patent Office.

signed and Sealed this 28th day-0f July, A.'D. 19m'.

Henr'y Ven Ar`sdale, (Seal) Acting Commissioner of Patents. 

